of protection failed to stop. tonight, harry smith examines a controversial solution that saves lives. >> we will be back. >> yeah. >> when i get my legs. >> also giant steps for the corcoran family in boston them mother and daughter whose recovery we have been following since the bombing and the heart and grit it takes to come back after a double amputation. >> being able to exercise my legs, as well as the rest of my body and work up a sweat, i don't feel broken when i'm doing that. i feel like i'm whole. i can do this. >> also tonight, can a marriage possibly be happily ever after when a husband suddenly decides to change sexes entirely? we will meet the family rewriting the definition of the new normal. >> is there anything you miss about having a husband? >> i miss, you know, walking through the world like a man and woman.